Electrical heating and forming method



Nov. 20, 1928. 1,692,488

A. G. DANNELL ELECTRICAL HEATING AND FORMING METHOD Filed May 11, 1927 3 Sheets-Sheet l (Swank;

Nov. 20, 1928.

' A. G. DANNELL ELECTRICAL HEATING AND FORMING METHOD Filed May 11, 3 Sheets-Sheet 2 Nov. 20, 1928. 1,692,488

A. G. DANNELL ELECTRICAL HEATING AND FORMING METHOD 1 1 1 May 11} i927 5 Sheets-sheet 3 Ewueutoz W W Patented Nov. 20, 1928i UN lTED STATES 1,692,488 PATENT OFFICE.

ARTHUR DANNELL, OF NEW YORK, N, Y., LASSIGNOR TO ELEKTROMATIK FORGING MACHINE CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRICAL HEATING. AND FORMING METHOD.

Application filed May 11,

My present invention relates to methods of heating and forging metal articles, and aims to devise means of the general character specified wherebv one or more of the metal articles to be heated and forged may have any desired portion or portions thereof heated to the desired forging temperature while being held in the forming (lie or the like, without, however, subjecting said die or the like to any undesirable or harmful electrical or heating effects, after which the article or articles so heated may be forged without subjecting the current and heat-applying means to any undesirable strains or actions resulting from the forging operation, the heating effect being preferably so localized as to avoid unduly heating and thus deteriorating the forming dies, and the forging or other forming operation being preferably so conducted as to avoid unduly straining or otherwise harming the current and heat-applying means. Other objects andadvantages of the methods of the present invention will in part be pointed out in detail hereinafter and will in part be obvious to those skilled in the art to which the present invention relates.

The present application is a continuation in part of my two copending applications, Serial No. 121,101 entitled- Forging machines, filed July 8, 1926, and Serial No. 121,102, entitled Metal articles, filed July 8, 1920.

In the accompanying specification I shall describe several illustrative embodiments of the methods of the present invention. In the accompanying drawing I shall diagrammatically illustrate the aforesaid illustrative embodiments of methods of the'same.

Referring to the drawing illustrating the aforesaid illustrative embodiments of the methods o'f-the present invention:

Fig. 1 a (.liagrammatic view illustrating one of the aforesaid illustrative embodiments of the methods of the present invention;

Fig. 2 is a diagrammatic view illustrating another of the aforesaid illustrative embodiments'of the present invention; a

Fig. 3 is a diagrammatic view illustrating still another of the aforesaid illustrative embodiments of the methods of the present in- I 1927. Serial No. 190,492.

Fi g. 5 is a diagrammatic view illustrating still another of the aforesaid illustrative embodiments of the methods of the present invention;

Fig. 6 is a similar view of an additional one of the aforesaid illustrative embodiments of the methods of the present invention; and

Fig. 7 is a similar view of still another one of the aforesaid illustrative embodiments of the present invention.

Referring now to the aforesaid illustrative embodiments of the present invention, the method may be described, in its broader aspects, as preferably embodying the following steps: the insertion in a die having one or more die cavities of one or more metal blanks or partially formed metal articles preferably corresponding in number to the number of cavities in the die. Of course, a series of dies may be employed with a corresponding series of articles in the cavity or cavities of each die. After the metal blanks or partially formed metal articles have been so inserted into the cavity or cavities in each of the dies, such metal blanks or partially formed articles are maintained, if already properly p0sitioned, or are now moved into heating position. Of course this step of elevating or lifting the blanks or partially formed articles into heating position is unnecessary'whe're the positions of such blanks or articles are initially such as are suitable for the heating operation.

Thereafter a plurality of electrodes, preferably of copper or other good electrical conducting material, are applied over the dies so that the current passes from a predetermined portion of one article through the portion of such article which it is desired-t0 heat and thenceout of such article into theother electrode or else through a bridging member,

likewise of copper or other good electrical conducting material to a predetermined point of a cooperating article where, as may be the case, two or a series of articles are being simultaneousl heated, and thence through the portion of t e second article which it is desired to heat and out of such portion by the remaining electrode. It will thus be seen that the heating eflect andthe operation of the current are limited to a predetermined portion or portions of one or more articles Without passing through the die which does not serve as an electrode. In other Words, the die is shunted out of the circuit and is thus not heated. In this way the injurious effect of the heating current on the die, where the die is a part of the circuit, as is almost universally the ease in the prior art, is avoided, the life of the die is greatly increased and the quality of the work produced is similarly improved. It may here be stated that where one article is being heated held in a single cavity in a die, the electrodes may be applied at the top and at the side of the article over and above the die, or the electrodes may be applied at different portions on the side of the article, thus localizing the heating effect to the por tion of the article included between the two electrodes. Where two or a series of articles are being simultaneously heated, the two electrodes, may be applied at the tops or ends of the articles, respectively, or at their sides, or one may be applied at the top of one of the articles and the other at the side of the remaining article, and the bridging member, which serves to shunt the heating current from the die, is applied to the sides of the two articles. Here again the heating current and thus the heating effect are localized and in neither case is the die subject to any undesirable electrical and heating effects which might serve to shorten its life and to render less accurate the quality of the work done by it.

In some cases where a plurality of metal blanks or partially formed articles are simultaneously to be heated for subsequent forging, such blanks or articles being located in corresponding cavities of a die, the bridging or shunting member may either be applied at intermediate portions of the metal blanks or articles, in which case the electrodes may both be placed either above or below such bridging or shunting member, thus causing the upperportions of the blanks or articles in the first case and lower portions of such blanks or articles in the second case to be heated, but all without heating the die; or else one electrode may be placed above the bridging or shunting member and the other electrode below such bridging or shunting member, in which case the upper portion of one of the articles and the lower portion of the other article will be heated to a forging temperature, in this case also without substantially heating the die. Or in some cases, the bridging or shunting member may be placed on the tops of the blanks or articles to be heated to a forging temperature, and the electrodes brought into contact with the desired intermediate portions of the articles to be heated to a forging temperature below the bridging or shunting member, thus heating the upper end portions of such. blanks or articles.

The particular arrangement of electrodes and bridging or shunting member in any particular case will depend upon the shapes and characters of the articles to be heated and the specific portions of such articles desired to be heated to a forging temperature, as well as on plane, the heat-applying means, including the electrodes and shunting member, being relatively stationary. In whichever way the contact is brought about, as by the move ment of the heat-applying means or of the articles to be heated, or both, the necessary degree of heat may be applied either in a single stage or, and m'e't'erably, in a succession of two or more heating stages, such as three heating stages, during the first of which the articles are given a prclin'iinary heat, during the second of which the articles are given an intermediate heat, and during the third of which the articles are given a final heat. n the ease of heating by successive stages, I prefer that the articles shall be intermittently moved past a series of heat-applying means, each of which may consist of one or more electrodes, or of a plurality of electrodes and a bridging or shunting member.

The heating operation being completed, the articles, having predetermined portions of thesame heated to a forging temperature, are now moved in their respective die cavities to bring them further into the die into forging position and are now brought into opera-.

ing the carrying die immediately under the forging or other forming die or other tool and the latter operated so as to be brought into forging relation to the heated portions of the articles.

The heating and forming operations being now completed, the finished articles may be ejected or otherwise removed from the containing die or dies in any suitable manner and by any suitable mechanism. For example, the same means which are employed to maintain or move the blanks or other articles to be heated into heating position and to subsequently move the same to bring the heating blanks or other articles into forging or other forming position, may be employed to eject the finished articles from the containing die or dies.

This completes the broad description of the operation of the methods of the present invention. It will be noted that by such methods one or more metal articles may have a predetermined portion or portions of the same heated to a forging temperature and forged Inn of the present invention the electric current is shunted or bridged away from the die which would otherwise be heated and have its fine edges burned away with consequent shortening of its life, increasing the expenses of the heating and forming operations, and deteriorating the quality of the work done. Other advantages and superioritics of the methods of the present invention will readily occur to those skilled in the art to which the present invention relates.

Turning now to the aforesaid illustrative embodiments of the methods of the present invention, and more particularly to the d rawings illustrating the same, Fig. 1 shows an arrangement inwhich the die 10 is provided with a cavity 10 in which the metal blank 11, which is to have a portionof the same heated to a forging temperature, rests. The dotted lines show the lowered position of the metal blank 11 corresponding to the-nonheating'and forming stages. The full lines indicate the position of the articles, 11 for the heating stage, for which purpose it is brought into contact with the electrodes 12 and 13, the electrode 12 being an upper electrode contacting with the upper face of the article 11, While the electrode 13 is a lateral electrode for contacting with an intermediate portion at the side of the article 11. The portion 11 of the article 11 to be heated will thus be lifted Well beyond the cavity 10 of the die 10 and heating current will pass substantially only through such portion,none of it passing through the die 10. A succession of such electrode'pairs 12 and 13 may be utilized if the heating is to take place in two or more stages, in which case the pairs of electrodes are locked. and the die and its contained blank will move substantially in a plane normal or perpendicular to the plane of the drawin Beyond the series of pairs of heating electrodes in the plane last described, may be positioned the forming die 14 carried by a tit) header 15 and having the forming cavity 14 which, by beingbrought into contact withthe heated portion 11' of the article has been first raised or elevated for the heating operation and subsequently lowered for the forming operation, gives to such heated portion 11' the desired form. The means 16 which may be utilized for elevating and lowering theblank 11 in the cavity 10' of the die 10, may be used for ejecting or otherwise removing such blank from the die. This constitutes a description of one embodiment of the method of the present invention as illustrated in Fig. 1 of the drawing. V

Turningnow to Fig. 2-of the .drawlng, there is shown illustrated an arrangement somewhat similar to that of Fig. 1 in which the electrodes 12' and 13 are both lateral electrodes, rather than one top and one lateral 'electrode,;as.shown in Fig. 1 of the drawing.

In this arrangement, the die has been desigheated by reference character 21". The formisn'g die has been designated by reference character 24', the cavity 1n the same by reference character 2 1' andthe header carrying the (he by reference character 25, 26 designating the means for elevating and lowering the blank 20 in its cavity 20 and for subsequently eject ingor otherwise removing the finished article. e

In Fig. 3 of the drawing, I have shown an arrangement/for simultaneously heating to a forging temperature and for subsequently forging portions of a plurality, such as two, articles. In this case, the die 30 has a plurality of cavities 30 and 30 in which may be disposed the blanks or other articles 31 and 32, the portions 31 and 32 of. which are to be heated toa forging temperature. Sucharticles, having been inserted in their respective die cavities, may now be elevated by the means 33 to the heating position, in which position they are brought into operative contact with the heat-applying means comprising the pair of electrodes 34 and 35 and the bridging or shunting member 36.

By means of the bridging or shunting memher the passage of the heating current, and thus the heating effect, is substantially limited to the portions 31 and 32- of the articles 31 and 32, respectively, which it is desired to heat to a forging temperature. For the subsequent forming operation the heated ends 31- and 32 of the articles 31 and 32, respectively, are lowered into forming position, if they have been previousl raised for the heating operation, and are rought into contact with the forming cavities 37 and 37" of the die member 37 carried by the header 38. The forming operation being completed, the plurality of formed articles may now be ejected or otherwise removed from the die 30, as by means of the mechanism 33 already referred to. I i

ion

' The arrangement of Fig. 1- of the drawing corresponds substantially to the arrangement shown in Fig. 3 of the drawing, except that the upper electrodes, here designated by ref;

characters 41 and'42; respectively, and the cavities in which such articles are located being designated by reference characters 40 and -40"1respectively, in. the die 40. vT he elevating, lowering .and ejecting mechanism has; "been des gnated by reference character 43,

"the bridgingorshunting member by reference :character. 46','i=whil e the forming die 47 is :shown provided -W1t-l1 the forming die cavitieszlfZand 4;: and the header carrying the die by reference character 48. Otherwise the arrangement and mode of operation are substantially the same as for the embodiment of the method illustrated in Fig. 3 of the drawing.

In Fig. 5 I have illustrated an arrangement somewhat analagous to that illustrated diagrammatically in Figs. 3 and 4 of the drawing, and in which the electrode 50 by a vertical motion, while the electrode 52 is laterally applied to the upper end of the article 53, the bridging or shunting member being designated by reference character 5d. The portions of the articles to be heated have been designated by reference characters 51 and 53, respectively. Here the die has been designated by reference character 55, the die cavities by reference characters 55 and 55 and the elevating,lowering and ejecting mechanism by reference character 56. The same type of heating mechanism may be employed as is shown in Figs. 3 and 4 of the drawing, and need not be further illustrated here.

In the arrangements shown in Figs. 2, 3,- f and 5, as in the arrangements shortly to be described in connection with the showings of Figs. 6 and 7 the heating may take place in a succession of stages by the successive intermittent movements of the articles past a series of heat-applying means, such as illustrated in the various figures of the drawings. Turning now to Fig. 6 of the drawing, the articles have been there designated by reference characters and 61 and the bridging or shunting member by reference character 62. As there illustrated, one electrode 63 is applied to the upper portion of the article 60 so as to heat the portion 60 of such article, while the other electrode 6a is applied just above the die to the lower portion of the article 61 to thus heat the portion 61 of the same. Otherwise the arrangement and mode of operation, including the forming operation, are the same as for the embodiments of the methods shown in Figs. 3, iand 5 of the drawing.

Referring now to Fig. 7 of the drawing, the articles. there designated'by reference characters 71 and 72 are provided with the bridging member 7 3 and the electrodes 74, 7 5 so as to heat only the lower portions 71 and 72 of the respective articles. In this case, an intermediate portion only of each article is heated to a forging temperature and the action ofv the forming die is to compress the heated intermcdiate material into the die cavities of the lower die 76, the upper die or forming member being designated by reference character 77.. Otherwise thearrangement of parts and mode of operation is the same as for the embodiments of the invention shown in Figs. 3, 4, 5 and 6 of the drawing.

It may here be stated that throughout th specification and claims, unless contrary meanings are indicated or are made necessary by the context, the terms elevating and lowering are not used in their absolute senses with reference to the vertical but are used in a relative sense as indicating movement out of or further out of, and into or furing said article in said die cavity so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavity, and heating said portion to a forging temperature while held in said die in such advanced position.

2. The method of heating a metal article held in a die cavity, which comprises supporting said article in said die cavity, so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavity, and electrically heating said portion to a forging temperature while held in said die in such advanced posi tion.

3. The method of heating a metal article held in a die cavity, which comprises supporting said article in said die cavity so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavity, and applying a plurality of electrical heating electrodes adjacent the extremes of said portion to pass heating current through said portion in such advanced position, without passing heating current through said die.

4. The method of heating a metal article held in a die cavity, which comprises supporting said article in said die cavity so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavity, and applying a plurality of electrical heating electrodes adjacent the extremes of said portion but above said die to pass heating current through said portion in such advanced position without passing heating current through said die.

5. The method of heating a metal article held in a die cavity, which comprises supporting said article in said die so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavity, and applying a plurality of electrical heating electrodes adjacent the extremes of said portion but above said die to pass heating current through said portion to heat the same to a forging temperature in such advanced position substantially without passing heating current through said die.

6. The method of heating a. plurality of metal articles held in a plurality of cavities in a die, which comprises supporting said artiloo cles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating-said portions to a forglng temperature whlle held in said die cavities in such advanced positions.

7. The method of heating a plurality of metal articles held in a plurality of cavities in a die, which comprises advancing said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature While held in said die cavities in suchadvanced positions.

8. The method of electrically heating a plurality of metal articles held in a plurality of cavities in a die, which comprises support ing said articles in said die cavities so that the portions desired to be heated extend be yond their respective die cavities, in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature while held in said die cavities in such advanced positions.

9. The method of electrically heating a plurality of metal articles held in a plurality of cavities in a die, which comprises advancing said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature while held in said die cavities in such advanced positions.

10. The method of electrically heating a plurality of metal articles held in a plurality of cavities in a die, which comprises advancing said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature While held in said die cavities by applying an electrical shunting member to said articles and a heat ing electrode to each of said articles so as to heat said portions of the same to a forging temperature in such advanced positions substantially without passing electric current through said die.

11. The method of electridally heating a plurality of metal articles held in a plurality of cavities in a die, which comprises supporting said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature While held in said die cavities by applying an electrical shunting member to said articles and a heating electrode to each of said articles so as to heat said portions of the same to a forging temperature-in such advanced positions substantially Without passing electric current through said die.

12. The method of heating a plurality of metal articles held in a plurality of cavities in a die, which comprises advancing said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature While held in said die cavities by applying an electrical bridging member to predetermined portions of said articles and a heating electrode to each of said articles so as to heat. desired portions of same electrically to a forging temperature by passing electric current through said portions in such advanced positions substantially Without passing electric current through said die.

13. The method of heating a plurality of metal articles held in a plurality of cavities in a die, which comprises supporting said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, and heating said portions to a forging temperature while held in said die cavities by applying an electrical bridging member to predetermined portions of said ar ticles and a heating electrode to each of said articles so as to heat desired portions of the same electrically to a forging temperature by passing electric current through said portions in such advanced positions substantially Without passing electric through said die.

14. The method of heating and forging a metal article held in a die cavity, Which comprises advancing said article in said die cavity so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavlty, applying a plurality of electrical heating electrodes adjacent the extremes of said portion but above said die to pass heating current through said portion to heat the same to a forging temperature without passing heating current through said die, removing said electrical heating electrodes, and retreating said article into forging position in said die cavity and thereafter forging the heated portion of the retreated article by bringing said heated portion of said article into operative contact with a forging die.

15. The method of heating and forging a metal article held in a die cavity, which comprises advancing said article in said die cavity so that the portion desired to be heated current Inn extends beyond said die cavity in advance of said article into forging position in said die cavity and thereafter forging the heated portion of the retreated article by bringing said heated portionof said article into operative contact with a forging die.

16. The method of heating and forging a metal article held in a die cavity, which comprises advancing said article in said die cavity so that the portion desired to be heated extendsbeyond said die cavity in advance. of its forging position in said die cavity, applying a plurality of electrical heating electrodes adjacent the extremes of said portion to pass heating current through said portion without passing heating current through said die, to heat said portion to a forging teniperature,

. removing said electrical heating electrodes,

and retreating said article into forging position in said die cavity and thereafter forging the heated portion of the retreated article by bringing said heated portion of said article into operative contact with a forging die.

17. The method of heating a metal article held in a die cavity, which comprises supporting said article in said die cavity so that the portion desired to be heated extends beyond said die cavity in advance of its forging position in said die cavity, electrically heating said portion to a forging temperature while held in said die in such advanced position, removing said electrical heating electrodes, and moving said article into forging position in said die cavity.

18. The method of heating a metal article held in a die cavity, which comprises supporting said article in said die cavity so that the portion desired to be heated extends beyond said die cavity in advance of'its forging position in said die cavity, heating said portion to a forging temperature while held in said die in such advanced position, removing said electrical heating electrodes, and moving said article into forging cavity.

19. The method of electrically heating and forging a plurality of metal articles held in a plurality of cavities in a die, which coinprises supporting said articles in said die cavities so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, bringing a portion of each of said articles into contact with an electrical shunting member and an electrical heating electrode to heat said portions to a forging temperature, removing said shunting member and electrodes, and thereafter bringing the heated portions of said articles into operative contact with forging means while retreating said articles into forging position in their respective die cavities and thereafter forging the heated portions of said articles in said retreated positions in their respective die cavities.

20. The method of heating and forginga plurality of metal articles held in a plurality of cavities in a die, which comprises support-. ing said articles in said die so that the portions desired to be heated extend beyond their respective die cavities in advance of their respective forging positions in their respective die cavities, bringing a portion of each of said articles into contact with an electrical shunting member and an electrical heating electrode to heat said portions to a forging temperature, removing said shunting member and electrodes, and thereafter bringing the heated portions of said articles into operative contact with forging means while retreating said articles into forging position in their respective die cavities and thereafter forging the heated portions of said articles in said retreated positions in their respective die cavities.

In testimony whereof I have signed my name to this specification this 10th day of May, 1927.

ARTHUR G. DANNELL.

position in said die 

